<!DOCTYPE html>
<html lang="cn">
<head>
    <meta charset="UTF-8">
    <title>SYS</title>
</head>
<body>
    <div align="center">
        {% if name %}
          <h1>Hello {{ name }}!</h1>
        {% else %}
          <h1>Hello, World!</h1>
        {% endif %}
    </div>
</body>
</html>